problem with scripts in Arduino Lab for MicroPython

Question

I am trying to set up an Arduino Nano ESP32 so that I can code in MicroPython. I successfully installed Arduino Lab for MicroPython and flashed the firmware onto the device, but when I try to run the sample code from the MicroPython Installation Guide, it fails, citing a syntax error. Curiously, it works fine when I run it through the REPL.

After spending a while trying to debug, I found something interesting. The following code yields the error "Traceback (most recent call last): File "<stdin>", line 11 SyntaxError: invalid syntax"

import time
while True:
 print("1")
 time.sleep(1)
 print("2")
 time.sleep(1)
 print("3")
 time.sleep(1)
 print("4")
 time.sleep(1)

However, if I get rid of the last two lines, it works fine. And once again, the full code works fine if I copy-paste into the REPL. What could be going wrong?

Edit: After spending some more time debugging, it looks like the failure is based on the number of characters in the script. Anything more than 128 characters causes it to fail.

• jsotola: do some basic debugging ... for example, what happens when you get rid of print("1") and print("2") ?
• Juraj: if you have an answer, write it please as answer, not as an update to the post

Answer 1

Upload the file manually with mpremote or ampy Install mpremote:

pip install mpremote

Upload your script:

mpremote connect /dev/ttyUSB0 fs put yourscript.py
mpremote connect /dev/ttyUSB0 run yourscript.py

This bypasses the Arduino Lab size limit.

Answer 2

It turns out that there was an incompatibility between MacOS and version 1.26.0 of the Arduino Nano ESP32 firmware. I reverted to v1.25.0, and now everything works.